1. Field of the Invention
This invention relates generally to high speed printing machines and more particularly to in-line printing apparatus for containers such as bottles or the like that are being successively moved along a predetermined path between a container production line and a container filling line.
2. Description of the Prior Art
The prior art printing apparatus generally employs intermittent motion in which the containers are first loaded, then moved step-wise, then stopped for the printing step and then linearly indexed away from the printing station. Prior art devices presently available are limited to a completion rate of about 60 to 80 containers a minute. Higher speeds have been claimed but have not been attained in practice. It will be readily apparent that the prior art mode of operation is excessively time consuming and therefore relatively costly. It will be equally apparent that an automated printing process that is integrated with both the container fabricating and the container filling production lines would be much more advantageous. The prior art devices, because of their "start-stop" mode of operation, interfere with the continuous running of the production line. More important, the limited speed of prior art printers prohibit an in-plant, in-line installation because most lines, especially for smaller size containers, fill at a rate of between 100 to 600 containers per minute.
As is well known in the industry, preprinted containers require average procurement lead time of from 6 to 8 weeks. Preprinted containers, of the type referred to, include plastic or glass bottles such as used by manufacturers of cosmetics, household items or foods or the like. Because of the wide variety of products that any particular manufacturer may be producing, it is necessary to have a large supply of containers of each size on hand at all times. For example, a manufacturer of cosmetics or household items may package from 10 to 15 items in identical containers in the usual sizes of 1/2 pint, 1 pint, 1 quart, etc. A full supply of each size container must be on hand covering at least the procurement lead time.
It will be appreciated that because of the wide variety of products that any one particular manufacturer may produce, it is necessary to have a large supply of containers of each size on hand at all times. For example, each item and each size container may be packaged under as many as 40 different distributor and private labels. The need for large inventories will become more apparent when it is realized that the quantities are based on projected sales schedules and that the actual sales may vary from these estimates. Further, when a specific item is ordered on a rush basis, it has, in the past, been necessary to wait until the containers were preprinted and, as mentioned above, this frequently takes 6 to 8 weeks.